How Mass and Social Media (De) polarize America: Exposure to News Media, Expression on Social Media, and Affective Polarization

This study examines the processes through which different modes of political communication (mass media use, social media use, and interpersonal discussion) jointly influence affective polarization. Drawing on the communication mediation framework, we hypothesize that partisan news use influences affective polarization through attitude extremity, as well as through political expression on social media and interpersonal conversation. Using a two-wave representative panel survey conducted during the 2020 U.S. presidential election, we found that like-minded news use intensifies affective polarization through attitude extremity and social media political expression and also through attitude extremity and interpersonal political discussion. Conversely, exposure to cross-cutting news mitigates affective polarization through these same pathways. The implications of these findings for political communication research are discussed.